Hey folks! Newbie here. I'm using a `class MyFragm...

# android

[Mihai Potra]

Hey folks! Newbie here. I'm using a class MyFragmentAdapter: FragmentStateAdapter subclass to use with a ViewPager2 list of fragments. Inside it I store an array of MyFragment: Fragment classes (i.e. MyFirstFragment: MyFragment and MySecondFragment: MyFragment) that I then instantiate inside FragmentStateAdapter.createFragment(position: Int) by invoking something like myClassesList[position].newInstance(). It is my understanding that instantiating MyFragment subclasses inside this function is better, because it manages memory allocation and deallocation (instantiate and destroy) automatically. But this means that I need to create MyFragment subclasses for each different Fragment even if code is the same, only layout differs.

My question is: Do object expression such as object: MyFragment { } also instantiate the Fragment? As far as I could read, these are only data classes, and do not allocate UI/state resources just from the Fragment constructor - onCreate() isn't invoked correct? And if I were to store in myClassesList the object: MyFragment(layout_id: R.layout.some_layout_id) could I still be able to somehow instantiate the Fragment inside createFragment(position: Int) ? Do I still need to "deallocate" objects or does Kotlin automatically sort that out for me when MyFragmentAdapter.myClassesList is destroyed?

[Mihai Potra]

On second thought: Is (MyFirstFrament::class.java).newInstance() pretty much the same as object: MyFirstFragment {} in terms of memory allocation (aside the anonymous object being a subclass of MyFirstFrament) ?

[Mihai Potra]

I think I may have answered myself above 🤦 - I ended up just storing the layout ids in the MyFragmentAdapter class, and instantiating MyFragment(layout_ids[position]) inside createFragment/1 so that no Fragment instances are created outside the Adapter. If I'm wrong on this, please anyone let me know

[Iliya Gogolev]

please read this https://stackoverflow.com/questions/10450348/do-fragments-really-need-an-empty-constructor

[Iliya Gogolev]

Also, it’s better to use a composable version of the view pager and avoid fragments 🙂